I have an MB4, but have never used prewound bobbins. I just wind a new one as the machine is stitching. Lynn
When I bought mine (the EP$ which is exactly the same) I got 2 boxes prewound cardboard sided bobbins; works fine for me, but not on my Designer1 which has a drop=in system.
I use prewound bobbins all so.I use the A size a have a janome 350 E.And a use them for my sewingmachine. I don't like the Card board I take the plastic bobbins.
I use prewound bobbins all the time and I love them. I use the L bobbins since my machines are all Brother. They are normally pretty pricy but chrck out this web site for great prices on all emb. threads and prewound bobbins. They last a lot longer than ones I wind myself. Try them but maks sure which your machine takes.
I ues prewound all the time and love them. I have to use the L bobbins since all my emb. machines are Brothers. They are normally pricy but check out the web site I've added at the bottom for some great prices on emb. threads plus prewound bobbins. They last longer than the ones I wind myself. Just make sure you only use ones that will work in your machine.
Exccuse the double post. Was trying to retype and correct typos but couldn't erase the first one. LOL Hugs